Are you tired of seeing this error inside your logs for Tomcat? Does your Tomcat run sluggishly? Do you use Netbeans? Do you want to revert Tomcat back to the state it used to be in, and can't figure out how? Follow this guide.

This very annoying problem is due to the fact that as soon as you add an external server to Netbeans, and tell it to monitor the HTTP traffic, it will install a Filter to apply to all HTTP requests, to pass directly to Netbeans, so that it may show it in the Monitor. This is a good thing, when Netbeans is running. However, as soon as Netbeans isn't running, your performance will fall dramatically, as the Tomcat server tries to connect to a non existing Netbeans, and pay the penalty of waiting to find that out, for every single HTTP request.

The solution is relatively simple however, if you are willing to hack away at Tomcat, As a word of caution, the following is a fix that I have repeatedly tried and works, but it is not a guaranteed solution, and screwing around with Tomcat might cause it to crash and require a restart. So you can't sue me if your computer bursts into a ball of flames after you tried to follow my advice, as I warned you it might not work!

Firstly, you need to stop the instance of Tomcat that is poorly

Next you need to navigate to your Tomcat Install Directory, and into the common directory, and then into libs. Inside here you will see a file called "org-netbeans-modules-web-httpmonitor.jar". Delete this, move it, or whatever your preference is, just don't let it exist inside that directory!

Now you need to edit the web.xml file inside the conf directory in the Tomcat Install Directory. You are looking for a block of XML that says something very similar to

Delete that block from the file, and save it.

Finally, you can restart Tomcat, free of any woes.